I highly recommend a visit to Bletchley for anyone interested, so many people overlooked and misrepresented in the movie. It also brushed over the fact that we had to be very careful how we used the information we got and not instantly saving a convoy at the first opportunity. We let people die...
The problem with history and films is that not all the facts are known due to the official secrets act. There is a memorial to the Polish part in cracking the Enigma machines at Bletchley Park (they did a lot of work on the simpler model) they massively helped by giving us all they had an act...